The JBO Thread Plug Gauge is a precision go/no-go tool designed to verify UNJC threads in drilled or tapped holes. Sized for 1/4 x 20 threads and right-hand orientation, it helps machinists, inspectors, and technicians quickly confirm that threaded holes meet the Unified thread standard without guesswork. Its compact design makes it a essential addition to any quality-control station in manufacturing, automotive, aerospace, and maintenance environments.

• Go/No-Go Verification: The two-limit design lets you quickly determine if a hole accepts a plug at the Go limit and rejects at the No-Go limit, speeding inspections and reducing the chance of misread threads.
• Rugged, Easy-Grip Body: Knurled surface provides secure handling in busy shop settings, improving handling precision and repeatable measurements.
• Right-Hand 3B UNJC 1/4 x 20 Specificity: Specifically matched to right-hand threads with 3B tolerance, ensuring consistent results across parts and tooling that follow the UNJC standard.

By incorporating the JBO Thread Plug Gauge into your inspection routine, you gain faster, more reliable thread checks that support first-pass quality, reduce rework, and streamline workflow. The clear go/no-go limits standardize inspections, making it easier to train operators and maintain traceability across batches. This gauge is designed for durable daily use and delivers consistent performance you can trust on every part.